Unless we can act collectively, there would be no way to defend ourselves, no way to define or enforce property rights. We couldn't curb congestion or pollution or build and maintain public infrastructure.

If top marginal income tax rates are set too high, they discourage productive economic activity. In the limit, a top marginal income tax rate of 100 percent would mean that taxpayers would gain nothing from working harder or investing more. In contrast, a higher top marginal rate on consumption would actually encourage savings and investment. A top marginal consumption tax rate of 100 percent would simply mean that if a wealthy family spent an extra dollar, it would also owe an additional dollar of tax.

Only the federal government has the power to spend beyond its current revenue. It shouldn't do that when the economy is at full employment. But it's an essential step for an economy mired in recession.

When the rich build bigger, they shift the frame of reference that shapes the demands of the near rich, who travel in the same social circles. Perhaps it's now the custom in those circles to host your daughter's wedding reception at home rather than in a hotel or country club. So the near rich feel they too need a house with a ballroom. And when they build bigger, they shift the frame of reference for the group just below them, and so on, all the way down.

One reason that might motivate a worker to accept a riskier job at higher pay, for example, would be that doing so would enable him to bid more effectively for a house in a better school district. But if other workers did likewise, none would achieve the goal they were striving for.

Getting the economy back on its feet is properly viewed as an investment in future prosperity. When businesses and consumers confront attractive investment opportunities, often the only way to seize them is by borrowing. The same is true for government. Contrary to the pronouncements of critics of economic stimulus, these investments will not impoverish our grandchildren. Continuing to allow the economy to languish in recession is the surest way to impoverish them.

In short both the things we feel we need and the things available for us to buy depend largely—beyond some point, almost entirely—on the things that others choose to buy.